1. Field of Invention
The invention relates to warming shoe pad and more particularly to a shoe having a heater unit mounted in the shoe pad for warming the foot wearing the shoe.
2. Description of Related Art
There have been numerous suggestions in prior patents for warming the foot wearing a shoe. For example, U.S. Pat. No. 3,935,856 (hereinafter “the '856 patent”) describes a shoe and foot warmer. The '856 patent discloses a metal base unit 20 and a metal external cap 13 hingedly connected to a forward hinge 14 on the base unit 20. Thus, the cap 13 is adapted to externally mount on a shoe 30 with a lower concave recess 33 fitted about a toe cap 31 of the shoe 30. A heater unit 10 fastens over the toe cap 31 by means of attached straps 11 and buckles 12. The base unit 20 is filled with cotton which holds the liquid fuel. A rotary damper valve 38 fits between wick (i.e., heating element) 16 and the base unit 20 for regulating the amount of fuel vapors reaching the wick 16 since the wick 16 is not in direct contact with the liquid fuel in the base unit 20. In operation, the hinged cap 13 is opened and the wick 16 is ignited to emit a steady glow. Then the cap 13 is closed to warm the attached toe cap 31 of the shoe 30 by heating the heater unit 10.
However, the '856 patent suffered from several disadvantages. For example, the externally mounted heater unit 10 is not visually aesthetic. Also, it may hinder walking while wearing the shoe. Further, the heater unit 10 may disengage with the shoe 30 if one or more fastening portions of the straps 11 and the buckles 12 loosen. Furthermore, heat transfer efficiency is low since the heater unit 10 is mounted externally on the shoe 30, i.e., the feet may still feel cold when wearing the shoes 30 mounted with the heater units 10. Thus, the need for improvement still exists.